A skyscraper is a tall, continuously habitable building having multiple floors. When the term was originally used in the 1880s it described a building of 10 to 20 floors but now describes one of at least 40-50 floors.
Rockefeller Center, built 1930-39, is a large complex consisting of 19 high rise commercial buildings covering 22 acres (89,000m) between 48th and 51st Streets in New York City. Commissioned by the Rockefeller family, it is located in the center of Midtown Manhattan, spanning the area between Fifth Avenue and Sixth Avenue. It was declared a National Historic Landmark in 1987
Mostly designed for office, commercial and residential uses a skyscraper can also be called a high-rise, but the term skyscraper is often used for buildings higher than 50m (164ft). For buildings above a height of 300m (984ft), the term Supertall can be used, while skyscrapers reaching beyond 600m (1,969 ft) are classified as Megatall. Currently, there are no megatalls in the Western Hemisphere.